1. Field of the Invention
The present invention relates to an illuminator and more particularly to a technique using a strip-shaped light guide.
2. Description of Related Art
Japanese Unexamined Patent Application Publication No. 2014-86202 discloses the following illuminator for a vehicle: multiple LEDs facing downward are arranged at some interval in the horizontal direction, multiple reflectors are disposed under the respective LEDs, the reflectors are arranged in the direction in which the LEDs are arranged, and a transparent strip-shaped front plate is disposed in front of the reflectors. The front plate, which is upright, extends in the horizontal direction. The thickness in the front-back direction of the front plate is smaller than the width in the up-down direction of the front plate. The front plate has a textured back surface. When the LEDs emit light and the front plate is seen from the front, the front plate looks luminous along a strip shape.
Unfortunately, the light emitted from the LEDs has high directional characteristics, and a part, in front of each reflector, of the front plate is more luminous than parts, in front of areas between the reflector and reflectors on both sides of the reflector, leading to unevenness in brightness in the front plate. That is, the front plate looks as if bright parts and dark parts are alternately disposed in the horizontal direction.